Erosional wear on piping located downstream of flow restricting devices is commonly caused by high velocity fluids jetting the inside surfaces of piping due to the high differential pressures across a flow restricting device. The fluids that are jetting the internal surfaces may contain impurities such as solids, which can erode the piping and reduce the effective life of the piping. The erosion in the internals of injection wellhead piping is caused by high pressure water jet streams that result from high differential pressure across chokes with the most significant damage found in piping of injection wells that have very low injection wellhead pressures. Traditional methods of installing blast tees or soft elbows to reduce erosional effects are used extensively in industry.
There have been a wide variety of devices used to restrict the flow of fluids by providing a fixed or automatically controlled restriction in a flow channels, conduits or tubulars. There are also a variety of devices used to address erosional issues that are associated with high velocity fluids in flow channels, conduits or tubulars.
If fluid flow velocity is decreased and the flow is dispersed, there will be a number of beneficial results. A number of attempts at holding back pressure and reducing fluid velocity have been made. In certain devices, a conventional choke design has been used and modified to try to accomplish a decrease in pressure and velocity. Examples of devices that have attempted to accomplish this include U.S. Pat. No. 5,771,922 (Fisher) entitled “For restricting fluid flow through a flow channel”; U.S. Pat. No. 4,234,008 (Cronfel) entitled “Fluid choke”; U.S. Pat. No. 3,921,672 (Arnold) entitled “Choke for controlling flow of pressurized fluid”, U.S. Pat. No. 3,072,261 (Smith) entitled “Sediment trapping hydraulic restriction”; and U.S. Pat. No. 2,501,593 (Becker) entitled “Flow bean”. Each of these devices have addressed pressure drop, reduced fluid velocity and recognized that there may be some solids in the flow.